diff --git a/go.mod b/go.mod
index 9520c8d9894..1725754b4db 100644
--- a/go.mod
+++ b/go.mod
@@ -33,9 +33,9 @@ require (
 	github.com/filecoin-project/go-cbor-util v0.0.0-20191219014500-08c40a1e63a2
 	github.com/filecoin-project/go-commp-utils v0.1.1-0.20210427191551-70bf140d31c7
 	github.com/filecoin-project/go-crypto v0.0.0-20191218222705-effae4ea9f03
-	github.com/filecoin-project/go-data-transfer v1.6.0
+	github.com/filecoin-project/go-data-transfer v1.7.0
 	github.com/filecoin-project/go-fil-commcid v0.0.0-20201016201715-d41df56b4f6a
-	github.com/filecoin-project/go-fil-markets v1.5.0
+	github.com/filecoin-project/go-fil-markets v1.6.0-rc1
 	github.com/filecoin-project/go-jsonrpc v0.1.4-0.20210217175800-45ea43ac2bec
 	github.com/filecoin-project/go-multistore v0.0.3
 	github.com/filecoin-project/go-padreader v0.0.0-20200903213702-ed5fae088b20
@@ -77,7 +77,7 @@ require (
 	github.com/ipfs/go-ds-pebble v0.0.2-0.20200921225637-ce220f8ac459
 	github.com/ipfs/go-filestore v1.0.0
 	github.com/ipfs/go-fs-lock v0.0.6
-	github.com/ipfs/go-graphsync v0.6.1
+	github.com/ipfs/go-graphsync v0.6.5
 	github.com/ipfs/go-ipfs-blockstore v1.0.3
 	github.com/ipfs/go-ipfs-chunker v0.0.5
 	github.com/ipfs/go-ipfs-ds-help v1.0.0
diff --git a/go.sum b/go.sum
index 86ac15b2c33..ee34abe5c3b 100644
--- a/go.sum
+++ b/go.sum
@@ -275,16 +275,16 @@ github.com/filecoin-project/go-commp-utils v0.1.1-0.20210427191551-70bf140d31c7/
 github.com/filecoin-project/go-crypto v0.0.0-20191218222705-effae4ea9f03 h1:2pMXdBnCiXjfCYx/hLqFxccPoqsSveQFxVLvNxy9bus=
 github.com/filecoin-project/go-crypto v0.0.0-20191218222705-effae4ea9f03/go.mod h1:+viYnvGtUTgJRdy6oaeF4MTFKAfatX071MPDPBL11EQ=
 github.com/filecoin-project/go-data-transfer v1.0.1/go.mod h1:UxvfUAY9v3ub0a21BSK9u3pB2aq30Y0KMsG+w9/ysyo=
-github.com/filecoin-project/go-data-transfer v1.6.0 h1:DHIzEc23ydRCCBwtFet3MfgO8gMpZEnw60Y+s71oX6o=
-github.com/filecoin-project/go-data-transfer v1.6.0/go.mod h1:E3WW4mCEYwU2y65swPEajSZoFWFmfXt7uwGduoACZQc=
+github.com/filecoin-project/go-data-transfer v1.7.0 h1:mFRn+UuTdPROmhplLSekzd4rAs9ug8ubtSY4nw9wYkU=
+github.com/filecoin-project/go-data-transfer v1.7.0/go.mod h1:GLRr5BmLEqsLwXfiRDG7uJvph22KGL2M4iOuF8EINaU=
 github.com/filecoin-project/go-ds-versioning v0.1.0 h1:y/X6UksYTsK8TLCI7rttCKEvl8btmWxyFMEeeWGUxIQ=
 github.com/filecoin-project/go-ds-versioning v0.1.0/go.mod h1:mp16rb4i2QPmxBnmanUx8i/XANp+PFCCJWiAb+VW4/s=
 github.com/filecoin-project/go-fil-commcid v0.0.0-20200716160307-8f644712406f/go.mod h1:Eaox7Hvus1JgPrL5+M3+h7aSPHc0cVqpSxA+TxIEpZQ=
 github.com/filecoin-project/go-fil-commcid v0.0.0-20201016201715-d41df56b4f6a h1:hyJ+pUm/4U4RdEZBlg6k8Ma4rDiuvqyGpoICXAxwsTg=
 github.com/filecoin-project/go-fil-commcid v0.0.0-20201016201715-d41df56b4f6a/go.mod h1:Eaox7Hvus1JgPrL5+M3+h7aSPHc0cVqpSxA+TxIEpZQ=
 github.com/filecoin-project/go-fil-markets v1.0.5-0.20201113164554-c5eba40d5335/go.mod h1:AJySOJC00JRWEZzRG2KsfUnqEf5ITXxeX09BE9N4f9c=
-github.com/filecoin-project/go-fil-markets v1.5.0 h1:3KEs01L8XFCEgujZ6ggFjr1XWjpjTQcmSSeo3I99I0k=
-github.com/filecoin-project/go-fil-markets v1.5.0/go.mod h1:7be6zzFwaN8kxVeYZf/UUj/JilHC0ogPvWqE1TW8Ptk=
+github.com/filecoin-project/go-fil-markets v1.6.0-rc1 h1:kQtND2NXz/cfGkjq+f5MCtz2oZAQabQvQ/zu4fppIps=
+github.com/filecoin-project/go-fil-markets v1.6.0-rc1/go.mod h1:S/C9PcSLFp75NpaF5aUqutnhXVJk6hM2dhWPYNq2jCQ=
 github.com/filecoin-project/go-hamt-ipld v0.1.5 h1:uoXrKbCQZ49OHpsTCkrThPNelC4W3LPEk0OrS/ytIBM=
 github.com/filecoin-project/go-hamt-ipld v0.1.5/go.mod h1:6Is+ONR5Cd5R6XZoCse1CWaXZc0Hdb/JeX+EQCQzX24=
 github.com/filecoin-project/go-hamt-ipld/v2 v2.0.0 h1:b3UDemBYN2HNfk3KOXNuxgTTxlWi3xVvbQP0IT38fvM=
@@ -627,8 +627,9 @@ github.com/ipfs/go-fs-lock v0.0.6/go.mod h1:OTR+Rj9sHiRubJh3dRhD15Juhd/+w6VPOY28
 github.com/ipfs/go-graphsync v0.1.0/go.mod h1:jMXfqIEDFukLPZHqDPp8tJMbHO9Rmeb9CEGevngQbmE=
 github.com/ipfs/go-graphsync v0.4.2/go.mod h1:/VmbZTUdUMTbNkgzAiCEucIIAU3BkLE2cZrDCVUhyi0=
 github.com/ipfs/go-graphsync v0.4.3/go.mod h1:mPOwDYv128gf8gxPFgXnz4fNrSYPsWyqisJ7ych+XDY=
-github.com/ipfs/go-graphsync v0.6.1 h1:i9wN7YkBXWwIsUjVQeuaDxFB59yWZrG1xL564Nz7aGE=
-github.com/ipfs/go-graphsync v0.6.1/go.mod h1:e2ZxnClqBBYAtd901g9vXMJzS47labjAtOzsWtOzKNk=
+github.com/ipfs/go-graphsync v0.6.4/go.mod h1:5WyaeigpNdpiYQuW2vwpuecOoEfB4h747ZGEOKmAGTg=
+github.com/ipfs/go-graphsync v0.6.5 h1:YAJl6Yit23PQcaawzb1rPK9PSnbbq2jjMRPpRpJ0Y5U=
+github.com/ipfs/go-graphsync v0.6.5/go.mod h1:GdHT8JeuIZ0R4lSjFR16Oe4zPi5dXwKi9zR9ADVlcdk=
 github.com/ipfs/go-hamt-ipld v0.1.1/go.mod h1:1EZCr2v0jlCnhpa+aZ0JZYp8Tt2w16+JJOAVz17YcDk=
 github.com/ipfs/go-ipfs-blockstore v0.0.1/go.mod h1:d3WClOmRQKFnJ0Jz/jj/zmksX0ma1gROTlovZKBmN08=
 github.com/ipfs/go-ipfs-blockstore v0.1.0/go.mod h1:5aD0AvHPi7mZc6Ci1WCAhiBQu2IsfTduLl+422H6Rqw=
diff --git a/itests/deals_concurrent_test.go b/itests/deals_concurrent_test.go
index d7932b896a5..241c9071dff 100644
--- a/itests/deals_concurrent_test.go
+++ b/itests/deals_concurrent_test.go
@@ -7,13 +7,13 @@ import (
 	"testing"
 	"time"
 
+	"github.com/filecoin-project/lotus/chain/actors/policy"
 	"github.com/stretchr/testify/require"
 
 	datatransfer "github.com/filecoin-project/go-data-transfer"
 	"github.com/filecoin-project/go-state-types/abi"
 
 	"github.com/filecoin-project/lotus/api"
-	"github.com/filecoin-project/lotus/chain/actors/policy"
 	"github.com/filecoin-project/lotus/itests/kit"
 	"github.com/filecoin-project/lotus/node"
 	"github.com/filecoin-project/lotus/node/modules"
@@ -56,14 +56,14 @@ func TestDealWithMarketAndMinerNode(t *testing.T) {
 		})
 	}
 
-	// TODO: add 2, 4, 8, more when this graphsync issue is fixed: https://github.com/ipfs/go-graphsync/issues/175#
-	cycles := []int{1}
+	// this test is expensive because we don't use mock proofs; do a single cycle.
+	cycles := []int{4}
 	for _, n := range cycles {
 		n := n
 		ns := fmt.Sprintf("%d", n)
 		t.Run(ns+"-fastretrieval-CAR", func(t *testing.T) { runTest(t, n, true, true) })
 		t.Run(ns+"-fastretrieval-NoCAR", func(t *testing.T) { runTest(t, n, true, false) })
-		t.Run(ns+"-stdretrieval-CAR", func(t *testing.T) { runTest(t, n, true, false) })
+		t.Run(ns+"-stdretrieval-CAR", func(t *testing.T) { runTest(t, n, false, true) })
 		t.Run(ns+"-stdretrieval-NoCAR", func(t *testing.T) { runTest(t, n, false, false) })
 	}
 }
@@ -73,6 +73,12 @@ func TestDealCyclesConcurrent(t *testing.T) {
 		t.Skip("skipping test in short mode")
 	}
 
+	oldDelay := policy.GetPreCommitChallengeDelay()
+	policy.SetPreCommitChallengeDelay(5)
+	t.Cleanup(func() {
+		policy.SetPreCommitChallengeDelay(oldDelay)
+	})
+
 	kit.QuietMiningLogs()
 
 	blockTime := 10 * time.Millisecond
@@ -95,8 +101,8 @@ func TestDealCyclesConcurrent(t *testing.T) {
 		})
 	}
 
-	// TODO: add 2, 4, 8, more when this graphsync issue is fixed: https://github.com/ipfs/go-graphsync/issues/175#
-	cycles := []int{1}
+	// this test is cheap because we use mock proofs, do various cycles
+	cycles := []int{2, 4, 8, 16}
 	for _, n := range cycles {
 		n := n
 		ns := fmt.Sprintf("%d", n)
@@ -107,13 +113,19 @@ func TestDealCyclesConcurrent(t *testing.T) {
 	}
 }
 
-func TestSimultenousTransferLimit(t *testing.T) {
+func TestSimultanenousTransferLimit(t *testing.T) {
 	if testing.Short() {
 		t.Skip("skipping test in short mode")
 	}
 
 	kit.QuietMiningLogs()
 
+	oldDelay := policy.GetPreCommitChallengeDelay()
+	policy.SetPreCommitChallengeDelay(5)
+	t.Cleanup(func() {
+		policy.SetPreCommitChallengeDelay(oldDelay)
+	})
+
 	blockTime := 10 * time.Millisecond
 
 	// For these tests where the block time is artificially short, just use
@@ -121,9 +133,14 @@ func TestSimultenousTransferLimit(t *testing.T) {
 	// so that the deal starts sealing in time
 	startEpoch := abi.ChainEpoch(2 << 12)
 
+	const (
+		graphsyncThrottle = 2
+		concurrency       = 20
+	)
 	runTest := func(t *testing.T) {
 		client, miner, ens := kit.EnsembleMinimal(t, kit.MockProofs(), kit.ConstructorOpts(
-			node.ApplyIf(node.IsType(repo.StorageMiner), node.Override(new(dtypes.StagingGraphsync), modules.StagingGraphsync(2))),
+			node.ApplyIf(node.IsType(repo.StorageMiner), node.Override(new(dtypes.StagingGraphsync), modules.StagingGraphsync(graphsyncThrottle))),
+			node.Override(new(dtypes.Graphsync), modules.Graphsync(graphsyncThrottle)),
 		))
 		ens.InterconnectAll().BeginMining(blockTime)
 		dh := kit.NewDealHarness(t, client, miner, miner)
@@ -145,7 +162,7 @@ func TestSimultenousTransferLimit(t *testing.T) {
 				select {
 				case u := <-du:
 					t.Logf("%d - %s", u.TransferID, datatransfer.Statuses[u.Status])
-					if u.Status == datatransfer.Ongoing {
+					if u.Status == datatransfer.Ongoing && u.Transferred > 0 {
 						ongoing[u.TransferID] = struct{}{}
 					} else {
 						delete(ongoing, u.TransferID)
@@ -160,16 +177,20 @@ func TestSimultenousTransferLimit(t *testing.T) {
 			}
 		}()
 
+		t.Logf("running concurrent deals: %d", concurrency)
+
 		dh.RunConcurrentDeals(kit.RunConcurrentDealsOpts{
-			N:             1, // TODO: set to 20 after https://github.com/ipfs/go-graphsync/issues/175 is fixed
+			N:             concurrency,
 			FastRetrieval: true,
 			StartEpoch:    startEpoch,
 		})
 
+		t.Logf("all deals finished")
+
 		cancel()
 		wg.Wait()
 
-		require.LessOrEqual(t, maxOngoing, 2)
+		require.LessOrEqual(t, maxOngoing, graphsyncThrottle)
 	}
 
 	runTest(t)
diff --git a/itests/kit/deals.go b/itests/kit/deals.go
index 4cee139253a..311db4b2582 100644
--- a/itests/kit/deals.go
+++ b/itests/kit/deals.go
@@ -292,6 +292,7 @@ func (dh *DealHarness) RunConcurrentDeals(opts RunConcurrentDealsOpts) {
 	for i := 0; i < opts.N; i++ {
 		i := i
 		errgrp.Go(func() (err error) {
+			defer dh.t.Logf("finished concurrent deal %d/%d", i, opts.N)
 			defer func() {
 				// This is necessary because golang can't deal with test
 				// failures being reported from children goroutines ¯\_(ツ)_/¯
@@ -299,11 +300,17 @@ func (dh *DealHarness) RunConcurrentDeals(opts RunConcurrentDealsOpts) {
 					err = fmt.Errorf("deal failed: %s", r)
 				}
 			}()
+
+			dh.t.Logf("making storage deal %d/%d", i, opts.N)
+
 			deal, res, inPath := dh.MakeOnlineDeal(context.Background(), MakeFullDealParams{
 				Rseed:      5 + i,
 				FastRet:    opts.FastRetrieval,
 				StartEpoch: opts.StartEpoch,
 			})
+
+			dh.t.Logf("retrieving deal %d/%d", i, opts.N)
+
 			outPath := dh.PerformRetrieval(context.Background(), deal, res.Root, opts.CarExport)
 			AssertFilesEqual(dh.t, inPath, outPath)
 			return nil